John, you touched on the fact that the soft rubber tears from the hard carcass on a tire that is not heat soaked. We have alot of problems at our track with exactly this. It is a slower speed track and VERY abrasive. Soft rear tires are destroyed and some medium cannot handle the task either.
Would you speculate it is because the tire cools down even while riding and the soft compound then tears? Is there anything you would suggest to minimize or eliminate this issue?
Just as background this happens with all the tire brands, while running the "proper" tire pressures and running at expert rider pace.
Oh boy!
The corners that really build heat or maintain heat are fast sweepers that you load the carcass, or are inputting steering for some time. Stratotech looks and from what I heard [I think that might be the one we're talking about] is a track that has short hard in type corners. And yes that could happen. If you don't maintain heat the the tire will cool and scrub off rubber.
At the same time,, if you have great asphalt and hard out type corners. That's a tough combo.
What I would do or recommend is some tests with the tire and see if the temperature is really falling off. On a normal day. So get a good tire probe style pyrometer. Do some laps and see what's going on inside the tire.
I think,,speculate might be better,, you may need to play with air pressure.
I do know last year at Mirabel,which is cement, the guys that actually got the wear out of the tires were running upwards of ten pounds more then the tire reps were suggesting. Cement is very abrasive and grippy, so by adding more pressure they reduced the contact patch. This reduced the grip and the tire didn't get as hot or abused.
You guys may be in the same situation. Someone would have to do some test.But you really need the good pyrometer, not infra red.And a good tire pressure gauge with fine increments.
If you are getting incredible grip it may be more then is necessary. I would think you should be able to find a pressure that would get you the grip and increase the life.Too much pressure and you will start spinning up which may lead to hi-sides.[Warning]
I think it sounds like one of those tracks where heat is being generated but grip is so good it just shreds the tire. If the tire wasn't generating heat you would start falling or sliding.
If that is not happening I think you need to go outside the box. Tire manufacturer's spec's are for perfect world scenarios,,,, Canada we're far from that,on a good day. We run what we can.
Okay, let me ask ,"has anyone ever experimented with slightly raised pressures and did it work?"
So what I would do,, good rider with discipline,, warmers on,, hot tire pressure. Five laps measure the temp and take the pressure.Five laps measure again. Add some air repeat. You have to start with hot tire pressures simply because coming off the track it will be hot.
We need to find out if the track design is causing it to loose heat and if not then we need to possible reduce the grip with increased hot pressure.
Now,,,,Please understand I'm not telling you to not listen to what the tire mfg'ers are saying to do. Document your findings then make calculated decisions as to what might help.
And ,, I'll try not to turn this into an "info-mercial" but some warmers do not get you the heat you need. You need good insulation and or some auxiliary insulation to ensure you have heat all the way through.
The one thing I've learned with warmers,,, is all things are not equal.So the farther up the lap time chart the more this becomes apparent.
So good pyrometer, probe style,good pressure gauge, good heat in the tire,, test away.
Hope this helps,,, if not sorry. What are your thoughts?
Can someone ask me a short question